Filtration systems

ABSTRACT

Filtration systems may comprise a manifold, a filter, a carriage, and a mounting mechanism. The manifold and the filter may each include an inlet fitting and an outlet fitting. The carriage may support the filter with the fittings of the manifold and filter respectively axially aligned. The mounting mechanism may be arranged between the manifold and the carriage to move the carriage and the filter between a disengaged position in which the filter fittings are spaced from the manifold fittings and an engaged position in which the filter fittings respectively engage the manifold fittings.

This application is a continuation of U.S. application Ser. No.10/275,862 filed May 5, 2003, which is the United States national phaseof International Application No. PCT/US01/15369, which was filed on May14, 2001, and is now U.S. Pat. No. 7,338,599, and claimed priority basedon U.S. Provisional Application No. 60/216,696 filed Jul. 7, 2000, andU.S. Provisional Application No. 60/203,946 filed May 12, 2000, all ofwhich are incorporated by reference.

TECHNICAL FIELD

The present invention relates to filtration which may be used in a widevariety of applications including, for example, the filtration of aphoto-resist liquid.

BACKGROUND OF THE INVENTION

Many fluids, such as photo-resist liquids used in the micro-electronicindustry, are exceedingly expensive. These liquids must be filteredimmediately prior to being used or impurities in the photo-resistliquids can damage the micro-electronic components being fabricated.

Conventional filtration systems and fitting arrangements for filtrationsystems have many problems associated with them. For example, thefiltration system may include a manifold connected to a pump which pumpsthe photo-resist liquid through the system. A filter which has one ormore fittings may be mounted to corresponding fittings on the manifold.However, conventional equipment used to mount the filter to the manifoldis often relatively large and occupies more space than is convenientlyavailable. Also, conventional mounting equipment can cause undue stresson the fittings, and potentially damage the fittings, because it failsto properly align the fittings as the filter is mounted to the manifold.Further, conventional mounting equipment is frequently difficult toaccess and maintain, often requiring disassembly of the manifold.

The fittings can also be mismatched due to variations in theirdimensions and eccentricity. Coupling mismatched fittings can alsoproduce undue stresses on the fittings due to misalignment. In addition,the mated fittings of many conventional systems have large volumes whichcollect or trap the photo-resist liquid, e.g., hold up volumes andleakage volumes. These hold up volumes and leakage volumes are expensivebecause the expensive liquid trapped in them is discarded when thefilter is replaced on the manifold. Further, the flow of fluid canstagnate in these hold up volumes and leakage volumes. When a liquidsuch as a photo-resist liquid stagnates, it can undergo chemical and/orphysical changes which can be detrimental to the fabrication process.

SUMMARY OF THE INVENTION

The present invention overcomes many problems associated withconventional filtration systems, including one or more of the problemspreviously described.

In accordance with one aspect of the invention, filtration systems maycomprise a manifold, a filter, a carriage, and a mounting mechanism. Themanifold may include an inlet fitting and an outlet fitting, eachfitting having an axis. The filter may include a housing and a filterelement disposed in the housing. The housing may include an inletfitting and an outlet fitting. Each fitting may have an axis and may bepositioned on top of the housing. The carriage supports the filter withthe fittings of the filter respectively aligned with the fittings of themanifold. The mounting mechanism may be arranged between the manifoldand the carriage to move the carriage and the filter between adisengaged position and an engaged position. In the disengaged position,the fittings of the filter are axially aligned with and spaced from thefittings of the manifold. In the engaged position, the fittings of thefilter respectively engage the fittings of the manifold. The filtermoves in a direction parallel to the aligned axes of the fittings of thefilter and the manifold along all of the distance that the filtertravels on the carriage.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a filtration system showing a manifold and acapsule filter disengaged.

FIG. 2 is a side view of the filtration system of FIG. 1.

FIG. 3 is a top view of the filtration system of FIG. 1.

FIG. 4 is a front view of the filtration system of FIG. 1 showing themanifold and the capsule filter engaged.

FIG. 5 is a partially sectioned top view of an alternative base assemblyof the filtration system of FIG. 1.

FIG. 6 is a partially sectioned side view of the base assembly of FIG. 5and a capsule filter mounted on the base assembly.

FIG. 7 is a partially sectioned top view of an alternative base assemblyof the filtration system of FIG. 1.

FIG. 8 is a side view of an alternative filtration system.

FIG. 9 is a partially sectioned front view of the filtration system ofFIG. 8.

FIG. 10 is a top view of the filtration system of FIG. 8.

FIG. 11 is a rear view of an upper portion of the filtration system ofFIG. 8.

FIG. 12 is a partially cutaway rear view of an upper portion of thefiltration system of FIG. 8.

FIG. 13 is a top view of the manifold of the filtration system of FIG.8.

FIG. 14 is a partially cutaway side view of an alternative mountingmechanism.

FIG. 15 is a top view of the mounting mechanism of FIG. 14.

FIG. 16 is a partially cutaway side view of an alternative mountingmechanism.

FIG. 17 is a top view of the mounting mechanism of the FIG. 16.

FIG. 18 is a partially cutaway side view of an alternative mountingmechanism.

FIG. 19 is a side view of the rotatable head of the mounting mechanismof FIG. 18.

FIG. 20 is a top view of the mounting mechanism of FIG. 18.

FIG. 21 is a partially cutaway side view of a centering mechanism.

FIG. 22 is a sectional side view of an alternative centering mechanism.

FIG. 23 is a partially cutaway top view of a portion of the centeringmechanism of FIG. 22.

FIG. 24 is a front view of a filtration system having an alternativedisengagement mechanism showing a manifold and a capsule filterdisengaged.

FIG. 25 is a front view of the filtration system of FIG. 24 showing themanifold and the capsule filter engaged.

FIG. 26 is a sectional view of a nozzle/receptacle arrangement showingthe nozzle and the receptacle disengaged.

FIG. 27 is a sectional view of the nozzle/receptacle arrangement of FIG.26 showing the nozzle and receptacle engaged.

FIG. 28 is a sectional view of an alternative nozzle/receptaclearrangement showing the nozzle and the receptacle disengaged.

FIG. 29 is a sectional view of the nozzle/receptacle arrangement of FIG.28 showing the nozzle and the receptacle engaged.

FIG. 30 is a sectional view of an alternative nozzle/receptaclearrangement showing the nozzle and the receptacle disengaged.

FIG. 31 is a sectional view of the nozzle/receptacle arrangement of FIG.30 showing the nozzle and the receptacle engaged.

FIG. 32 is a sectional view of an alternative nozzle/receptaclearrangement showing the nozzle and receptacle disengaged.

FIG. 33 is a sectional view of the nozzle/receptacle arrangement of FIG.32 showing the nozzle and receptacle engaged.

FIG. 34 is a sectional view of an alternative nozzle/receptaclearrangement showing the nozzle and the receptacle disengaged.

FIG. 35 is a sectional view of the nozzle/receptacle arrangement of FIG.34 showing the nozzle and the receptacle engaged.

FIG. 36 is a sectional view of an alternative nozzle/receptaclearrangement showing the nozzle and the receptacle disengaged.

FIG. 37 is a sectional view of the nozzle/receptacle arrangement of FIG.36 showing the nozzle and the receptacle engaged.

FIG. 38 is a sectional view of an alternative nozzle/receptaclearrangement.

FIG. 39 is a sectional view of an alternative nozzle/receptaclearrangement.

FIG. 40 is a sectional view of an alternative nozzle/receptaclearrangement.

FIG. 41 is a sectional view of an alternative nozzle/receptaclearrangement.

FIG. 42 is a side view of the capsule filter.

FIG. 43 is a rear view of the capsule filter of FIG. 42.

FIG. 44 is a top view of the capsule filter of FIG. 42.

FIG. 45 is a sectional side view of the capsule filter of FIG. 42.

FIG. 46 is a side view of a filter cartridge of the capsule filter ofFIG. 45.

FIG. 47 is a sectional side view of an alternative capsule filter.

FIG. 48 is a sectional side view of an alternative capsule filter.

FIG. 49 is a sectional side view of an alternative bowl of a capsulefilter.

FIG. 50 is a top view of the bowl of FIG. 49.

FIG. 51 is a sectional side view of an alternative bowl.

FIG. 52 is a top view of the bowl of FIG. 51.

DESCRIPTION OF EMBODIMENTS

One example of a filtration system 10 embodying the invention is shownin FIGS. 1-4. The filtration system 10 generally comprises aloading/unloading equipment, e.g., a carriage 11, and further comprisesa manifold 12 and a filter such as a capsule filter 13. The capsulefilter includes a filter medium, and the manifold 12 and the capsulefilter 13 may include mating fittings 14, 15, e.g., inlet fittings 14 a,15 a, outlet fittings 14 b, 15 b, and vent fittings 14 c, 15 c. Thecarriage 11 supports the capsule filter 13 and is cooperatively arrangedwith the manifold 12 to mount the capsule filter 13 to the manifold 12and engage the fittings 15 of the capsule filter 13 with the respectivefittings 14 of the manifold 12. For example, a mounting mechanism 16 maybe arranged between the carriage 11 and the manifold 12 to move thecapsule filter 13, e.g., longitudinally, between a disengaged position,as shown in FIGS. 1 and 2, and an engaged position, as shown in FIG. 4.In the disengaged position, the capsule filter 13 may rest in thecarriage 11 and may be spaced from the manifold 12. In the engagedposition, the capsule filter 13 engages the manifold 12, and thefittings 14, 15 of the manifold 12 and the capsule filter 13 are sealedto one another.

With the fittings 14, 15 engaged, a pump 17, which may be fluidlycoupled and even directly attached to the manifold 12, pumps fluid,e.g., a liquid such as a liquid photo resist, into an inlet conduit inthe manifold 12, through the inlet fittings 14 a, 15 a, and into thecapsule filter 13. Gases, such as air contained in the capsule filter 13or gas bubbles entrained in the liquid, may be vented from the capsulefilter 13 via the vent fittings 14 c, 15 c and a vent conduit 20 of themanifold 12. Filtered liquid is forced by the pump through the filtermedium of the capsule filter 13 and out of the capsule filter 13 via theoutlet fittings 14 b, 15 b and an outlet conduit 21 of the manifold 12.

Once the filter medium of the capsule filter 13 becomes sufficientlyfouled, the pump 17 may be deactivated and the carriage 11 may be moved,e.g., lowered, by the mounting mechanism 16 to the disengaged position.A disengagement mechanism 22 may be coupled between the capsule filter13 and the carriage 11 and/or the manifold 12 to disengage the fittings15 of the filter capsule 13 from the fittings 14 of the manifold 12 asthe carriage 11 is lowered. Alternatively, the capsule filter 13 may bedisengaged from the manifold 12 manually. The old capsule filter 13 maythen be replaced with a new capsule filter 13; the carriage 11 may bemoved, e.g., raised, by the mounting mechanism 16 to the engagedposition engaging the new capsule 13 with the manifold 12; and the pump17 may then be reactivated.

The carriage 11 may be configured in a wide variety of ways. In maypreferred embodiments, the carriage 11 may be arranged to move thecapsule filter 13, both into and out of engagement with the manifold 12,in a direction parallel to the axes of the engaged fittings 14, 15. Morepreferably, the carriage 11 moves the capsule filter 13 in a directionparallel to the axes of the engaged fittings 14, 15 along most of, evenmore preferably, substantially all of, the distance that the capsulefilter 13 travels on the carriage 11.

In one example, shown in FIGS. 1 and 2, the carriage 11 may include abase assembly 23, a top assembly 24, and first and second preferablyidentical side assemblies 25 which extend between the top assembly 24and the base assembly 23. The base, top, and side assemblies may eachcomprise any of a wide array of suitable structures, includingmulti-piece structures. However, in many preferred embodiments, the baseassembly 23 comprises a base 26, such as a base plate, which supportsthe capsule filter 13 and on which the capsule filter 13 rests. Further,the side assemblies 25 each comprise side plates 30 which are connectedto the base 26. The side plates 30 preferably extend parallel to eachother closely along the exterior of the sides of the manifold 12 to thetop assembly 24. The manifold 12 may include guide channels 29 withinwhich the side plates 30 slide, e.g., upwardly and downwardly, as thecarriage 11 moves between the disengaged and engaged positions.Alternatively, the manifold may include pins or rollers which engageslots or tracks on the side plates. In addition, the top assembly 24 maycomprise a top plate 31 which is connected to the side plates 30 andextends along the top of the manifold 12. The carriage 11 thus surroundsthe exterior of the manifold 12 and is preferably accessible formaintenance without having to disturb the manifold 12, e.g., dismantlethe manifold 12 from the pump 17.

As another example, the carriage may comprise a base assembly andopposite side assemblies without a top assembly. The carriage may thenbe operatively associated with the manifold in any suitable manner, forexample, by connecting the side assemblies of the carriage to the sidesor the bottom of the manifold via a mounting mechanism. As yet anotherexample, the carriage may be operatively associated with a structureother than the manifold. For example, when the manifold is attached to apump, the carriage may also be coupled to the pump, rather than themanifold, and arranged to move the capsule filter between engagement anddisengagement with the manifold.

In many preferred embodiments, the base plate and the side platescomprise a generally U-shaped assembly adapted to support the capsulefilter, and the carriage thus comprises a compact, highly spaceefficient structure for supporting the capsule filter. For example, thecarriage and the capsule filter may be installed in a space having arelatively small width, e.g., a width of is about 60 millimeters orless, compared to a width of about 140 millimeters or more required formany conventional filter mounting mechanisms. The capsule filter 13 canthus be mounted and dismounted within a 60-millimeter-wide front area.Especially when combined with a 60 millimeter-wide pump, a filtrationsystem embodying the present invention provides a dispensing system thathas a high space utilization efficiency but is nonetheless easilyaccessible and therefore easy to use and maintain.

In the disengaged position, the carriage preferably supports the filtercapsule on the base assembly. The filtration system may also include apositioning mechanism which allows the capsule filter to be positionedand oriented on the base assembly with the fittings of the capsulefilter at least roughly aligned with the fittings of the manifold. Thepositioning mechanism may be operatively associated with the carriageand/or the capsule filter and may take a variety of forms. In theembodiment of FIGS. 1-4, the positioning mechanism 32 is cooperativelyarranged with the base 26 and may include a rear wall 33 which limitsthe rearward movement of the capsule filter 13. The rear wall may extendfrom the base assembly or from one or both of the side assemblies.Further, the positioning mechanism 32 may include an opening such as anelongated slot 34 which extends within the base 26 from the front edgeand a corresponding elongated tab or protrusion 35 which extends fromthe bottom of the capsule filter 13. The slot 34 and the protrusion 35may be dimensioned to limit the rearward movement of the capsule filter13 on the base 26 and/or to angularly orient the capsule filter 13 onthe base 26 with the fittings 15, 14 at least roughly aligned with oneanother. With the capsule filter 13 positioned on the base 26, thecapsule filter 13 may slide rearwardly along the base 26 with theprotrusion 35 sliding within the slot 34. The close proximity of thesides of the slot 34 and the sides of the protrusion 35 maintain thecapsule filter 13 at a desired angular orientation with respect to themanifold 12. Once the backside of the capsule filter 13 contacts therear wall 33 and/or the backside of the protrusion 35 contacts thebackside of the slot 34, the axes of the fittings 14, 15 are at leastroughly aligned axially. The capsule filter 13 may then be mounted tothe manifold 12 without damaging the fittings 14, 15 due tomisalignment.

The positioning mechanism is not limited to the embodiment shown inFIGS. 1-4. For example, as shown in FIGS. 5 and 6, the rear wall may beeliminated and the positioning mechanism may comprise openings such asone or more holes 36 in the base 26 and one or more correspondingprotrusions 37 extending from the bottom of the capsule filter 13. Thecapsule filter 13 is positioned on the base 26 with the protrusions 37of the capsule filter 13 disposed in the holes 36 of the base 26. Theprotrusions 37 and the holes 36 are dimensioned and located on thecapsule filter 13 and the base 26, respectively, such that when theprotrusions 37 are disposed in the holes 36, the fittings 14, 15 of themanifold 12 and the capsule filter 13 are at least roughly alignedaxially. The embodiment shown in FIGS. 5 and 6 has two holes 36 and twoprotrusions 37. However, the positioning mechanism may comprise morethan two holes and protrusions, e.g., three holes and protrusions spacedfrom one another in a triangular configuration, or only one hole andprotrusion, e.g., an elongated hole 28 (and a corresponding protrusion)as shown in FIG. 7. Further, while the positioning mechanisms of theillustrated embodiments have been associated with the base assembly, thepositioning mechanism may be associated with the carriage in other ways,e.g., with the side assemblies. For example, the positioning mechanismcan be associated with the rear wall 33 of the base 26 as shown in FIGS.8-9.

Once the capsule filter 13 is positioned on the carriage 11, thecarriage 11 is moved from the disengaged position toward the engagedposition by the mounting mechanism. The mounting mechanism may also takea variety of forms, and one example of a mounting mechanism 16 is shownin FIGS. 1-4. The mounting mechanism 16 is preferably cooperativelyarranged between the carriage 11 and the manifold 12 and in someembodiments may comprise a threaded arrangement including a threadedstud 40 and a mating nut 41, which may be part of a knob 42. Thethreaded stud 40 may have trapezoidal threads and is preferably fixedlymounted to the top of the manifold 12 extending toward the top assembly24 of the carriage 11. The nut 41 is correspondingly threaded and ispreferably rotatably mounted to the top assembly 24, e.g., the top plate31, to receive the stud 41 in threaded engagement. As the knob 42 isrotated in one direction, the nut 41 moves axially in one directionalong the stud 40, e.g., away from the manifold 12, and, in turn, movesthe base 26 of the carriage 11 from the disengaged position toward themanifold 12 and the engaged position, where the fittings 15 of thecapsule filter 13 engage the fittings 14 of the manifold 12. As the knob42 is turned in the opposite direction, the nut 41 moves axially in theopposite direction along the stud 40 (e.g., toward the manifold 12) and,in turn, moves the base 26 of the carriage 11 back toward the disengagedposition. The threads may be arranged to provide a quick release of thecapsule filter 13 from the manifold 12. For example, the threads may bearranged such that turning the knob 42 in the range from about 90degrees to about 360 degrees may be enough to release the capsule filter13 from the manifold 12.

Alternatively, the mounting mechanism may comprise a threaded stud and acorrespondingly threaded portion of the top assembly of the carriage,which receives the threaded stud. One end of the threaded stud may bepart of a knob and the opposite end of the stud may bear against, or maybe rotatably fixed to, the top of the manifold. This embodiment of themounting mechanism operates in a manner similar to the mountingmechanism 16 shown in FIGS. 1-4.

Another example of a mounting mechanism 16 is shown in FIGS. 8-13.(Components of the embodiment shown in FIGS. 8-13 have the samereference numbers as the analogous components of the embodiments shownin FIGS. 1-7.) The mounting mechanism 16 shown in FIGS. 8-13 ispreferably cooperatively arranged between the carriage 11 and themanifold 12 and may comprise a pivotable lever arrangement including alever 51 which is pivotable about a pivot axis 52. The lever may becoupled between the manifold and the carriage in a variety of ways. Forexample, the lever 51 may be pivotably mounted by pivot pins 53 to abracket 54 which, in turn, may be mounted to the top of the manifold 12.Alternatively, the lever 51 may be mounted to brackets on the sides ofthe manifold. The lever 51 may also be mounted to the carriage 11 in avariety of ways, e.g., to the side assemblies 25. The lever 51 ispreferably arranged to lift the carriage 11 from the disengaged positiontoward the engaged position as the lever 51 is lifted and to lower thecarriage 11 from the engaged position toward the disengaged position asthe lever 51 is lowered. The mounting mechanism 16 may also include aspring arrangement 55 for biasing the lever 51 toward a lifted and/orlowered position, maintaining the carriage 11 in the engaged and/ordisengaged position.

Other examples of mounting mechanisms, e.g., mounting mechanismscomprising a cam arrangement, are shown in FIGS. 14-20. (Again,components of the embodiments shown in FIGS. 14-20 have the samereference numbers as the analogous components of the embodiments shownin FIGS. 1-13.) For example, the mounting mechanism 16 shown in FIGS. 14and 15 may comprise a removable or fixed lever 61 connected to arotatable shaft 62 which, in turn, is rotatably connected to themanifold 12 by a mounting plate 63. The lever 61 extends through a camslot 64 in a head 65 which may be fixedly attached to the top assembly24 of the carriage 11, e.g., at the top plate 31. As the lever 61 ismoved along the cam slot 64, the head 65 and hence the carriage 11 israised or lowered between the disengaged position and the engagedposition.

A similar mounting mechanism 16 is shown in FIGS. 16 and 17. Themounting mechanism 16 may include a pin 66 which extends radially fromthe rotatable shaft 62. The pin 66 is disposed in the cam slot 64 of thefixed head 65. The cam slot 64 may extend completely through the head65, as in the embodiment shown in FIG. 14, or it may merely extendpartially into the inner periphery of the head 65. A structure 67 formedat the end of the shaft 62 may be engaged by a wrench, e.g., an allenwrench, to turn the shaft 62. Alternatively, the shaft may extendaxially beyond the head and the protruding end of the shaft may beformed as a knob which may be turned manually. As the shaft 62 isturned, the pin 66 rides along the cam slot 64, and the head 65 andhence the carriage 11 is raised or lowered between the disengagedposition and the engaged position.

Another example of a mounting mechanism 16 which comprises a camarrangement is shown in FIGS. 18-20. The mounting mechanism 16 mayinclude a nonrotatable shaft 71 fixed to the manifold 12 and having aradially extending pin 72. The pin 72 is disposed in a cam slot 73 of ahead 74 which is rotatably attached to the top assembly 24 of thecarriage 11 by a mounting plate 75. Holes 76 in the head 75 receive aremovable lever 77, e.g., a screwdriver, which can be used to rotate thehead 74 on the shaft 71. Alternatively, the lever may be fixed to thehead; the head may be formed with a structure that can be turned with awrench; or the head may be formed as a knob that can be turned manually.As the head 75 is rotated, the pin 72 rides along the cam slot 73, andthe head 74 and hence the carriage 11 is raised or lowered between thedisengaged position and the engaged position.

As the carriage 11 is moved toward the manifold 12 from the disengagedposition to the engaged position, the fittings 15 of the capsule filter13 approach the fittings 14 of the manifold 12. The fittings 14, 15 maybe at least roughly aligned by the positioning mechanism. However, tomore closely align the fittings 14, 15, the filtration system 10 mayinclude a centering mechanism which closely aligns the axes of thefittings 14, 15 as they engage one another. The centering mechanism maybe configured in a wide variety of ways. For example, the centeringmechanism 80 may comprise one or, preferably, a plurality of centeringprotrusions, e.g., centering pins 81, which fit into correspondingcentering apertures 82 as the fittings 14, 15 engage each other. Asshown in FIG. 21, the centering pins 81 may extend upwardly from thecapsule filter 13, e.g., the top of the capsule filter 13, and thecorresponding centering apertures 82 may be disposed in the manifold 12,e.g., the bottom of the manifold 12. Alternatively, as shown in FIGS. 22and 23, the centering pins 81 may extend from the bottom of the manifold12 and the centering apertures 82 may be disposed in the top of thecapsule filter 13.

The centering mechanism 80 is preferably located and dimensioned toensure that the fittings 14, 15 are closely axially aligned as theysealingly contact one another. For example, the centering pins 81 andapertures 82 may have relatively close tolerances and may be arranged toclosely engage one another before the fittings 14, 15 fully contact andare completely sealed to one another. With the centering pins 81 closelyengaged with the centering apertures 82, the fittings 14 of the manifold12 may be moved into full sealing contact with the fittings 15 of thecapsule filter 13. The centering mechanism 80 thus prevents incompletesealing and/or damage to the fittings 14, 15 due to misalignment. Thecentering mechanism 80 may also serve as a stop, limiting the advance ofthe fittings 14, 15 within each other and preventing over compression.Alternatively, stops may be provided elsewhere on the manifold and thecapsule filter and/or the carriage.

As the carriage 11 is moved away from the manifold 12 from the engagedposition to the disengaged position, the fittings 15 of the capsulefilter 13 may be disengaged from the fittings 14 of the manifold 12. Insome embodiments, the fittings 14, 15 of the manifold and the capsulefilter 13 may remain engaged as the carriage 11 is moved to thedisengaged position, the base assembly 23 of the carriage 11 moving awayfrom the bottom of the capsule filter 13 as the carriage 11 moves to thedisengaged position. The capsule filter 13 may then be removed from themanifold 12, e.g., by manually disengaging the fittings 15 of thecapsule filter from the fittings 14 of the manifold 12.

Alternatively, the filtration system 10 may further comprise adisengagement mechanism which is operatively associated with the capsulefilter 13 and automatically disengages the fittings 15 of the capsulefilter 13 from the fittings 14 of the manifold 12 as the carriage 11moves toward the disengaged position. The disengagement mechanism may beconfigured in a variety of ways. For example, the disengagementmechanism may be cooperatively arranged between the capsule filter 13and the manifold 12. One example of such a disengagement mechanism 22 isshown in FIGS. 22 and 23 and comprises one or more springs 86 disposedbetween the capsule filter 13 and the manifold 12. The springs may bepositioned in a variety of suitable locations between the capsule filterand the manifold. In the illustrated embodiment, a spring 86 is disposedaround each centering pin 81. The springs 86 are compressed around thecentering pins 81 as the carriage 11 is lifted to the engaged positionby the mounting mechanism 16 and the fittings 15 of the capsule filter13 are lifted into sealing contact with the fittings 14 of the manifold12. As the carriage 11 is lowered to the disengaged position by themounting mechanism 16, the springs 86 expand and automatically disengagethe fittings 14, 15. The centering mechanism 80 also helps to maintainaxial alignment of the fittings 14, 15 as the fittings 14, 15 aredisengaged by the disengagement mechanism 22. The capsule filter 13remains on the base assembly 23 of the carriage 11 as the carriage 11 ismoved to the disengaged position

In other embodiments, the disengagement mechanism may be cooperativelyarranged between the capsule filter 13 and the carriage 11. One exampleof such a disengagement mechanism 22 is shown in FIGS. 1 and 4 andcomprises one or more push rods 91 disposed between the carriage 11 andthe capsule filter 13. The push rods may be positioned in a variety ofsuitable locations between the capsule filter and the carriage. In theillustrated embodiment, the push rods 91 are disposed in through holes92 in the manifold 12 between the top of the capsule filter 13 and thetop assembly 24 of the carriage 11. The push rods 91 may be lifted alongwith the capsule filter 13 and the carriage 11 as the carriage 11 ismoved to the engaged position by the mounting mechanism 16. As thecarriage 11 is lowered to the disengaged position by the mountingmechanism 16, the top assembly 24 of the carriage 11 may bear againstthe push rods 91. The push rods 91, in turn, bear against the top of thecapsule filter 13, forcing the capsule filter 13 away from the manifold12 and automatically disengaging the fittings 14, 15. The capsule filter13 remains on the base assembly 23 of the carriage 11 as the carriage 11is moved to the disengaged position.

Another example of a disengagement mechanism 22 cooperatively arrangedbetween the carriage 11 and the capsule filter 13 is shown in FIGS. 24and 25. (Components of the embodiment shown in FIGS. 24 and 25 have thesame reference numbers as the analogous components of the embodimentshown in FIGS. 1-4.) The disengagement mechanism 22 generally comprisesa fitment which physically couples the capsule filter 13 and thecarriage 11 as the carriage 11 moves between the engaged position andthe disengaged position. The fitment may be structured in a wide varietyof ways. In the illustrated embodiment the fitment 96 comprises theengagement of the base assembly 23 of the carriage 11 with the capsulefilter 13, e.g., with a flange 97 extending from the protrusion 35 inthe bottom of the capsule filter 13 past the edges of the slot 34 in thebase 26. As the carriage 11 is lowered to the disengaged position by themounting mechanism 16, the base 26 of the carriage 11 bears against theflange 97 of the capsule filter 13, forcing the capsule filter 13 awayfrom the manifold 12 and automatically disengaging the fitting 15 of thecapsule filter 13 from the fittings 14 of the manifold 12. The capsulefilter 13 remains on the base assembly 23 of the carriage as thecarriage 11 is moved to the disengaged position.

Another example of a fitment is a flange which extends from each sideassembly of the carriage over the top of the capsule filter. As thecarriage is lowered by the mounting mechanism, the flanges of the sideassemblies may bear against the top of the capsule filter, automaticallydisengaging the capsule filter from the manifold.

The manifold 12 may also be configured in a wide variety of ways. Forexample, the manifold may have any regular or irregular shape. As shownin FIGS. 1-4, the manifold 12 may have a box-shaped configurationincluding a front 100, a back 101, a top 102, a bottom 103 and oppositesides 104, 105. The manifold 12 may further include one or more conduitsfor transporting fluid to and/or from the capsule filter. Each of theconduits is preferably configured to reduce hold up volume and to avoiddead volumes or zones where the fluid can stagnate.

In many preferred embodiments, the manifold 12 is fluidly coupled to apump 17. For example, the manifold 12 may be directly attached to thepump 17, e.g., along the back 101 of the manifold 12. The outlet of thepump 17 may be connected to an inlet conduit of the manifold 12 whichextends through the manifold 12 and fluidly communicates, in turn, withthe inlet fittings 14 a, 15 a of the manifold 12 and the capsule filter13. Alternatively, the inlet conduit may be at least partially externalto the manifold, e.g., extending externally from the pump to themanifold and hence to the inlet fittings. The manifold 12 may alsoinclude an outlet conduit 21 which fluidly communicates between theoutlet fittings 14 b, 15 b and any other appropriate component of thefluid system downstream of the manifold 12. In the illustratedembodiment, the outlet conduit 21 may extend from the outlet fittings 14b, 15 b through the manifold 12 to the front 100 of the manifold 12.However, the outlet conduit may extend from any portion of the manifold,including the top of the manifold. The manifold 12 may further include avent conduit 20 which fluidly communicates between the vent fittings 14c, 15 c and any appropriate reservoir for the vented gas. Again in theillustrated embodiment, the vent conduit 20 may extend from the ventfittings 14 c, 15 c through the manifold 12 to the front 100 of themanifold 12. However, the vent conduit may extend from any portion ofthe manifold, including the top of the manifold. In some embodiments,the vent conduit, as well as the vent fittings, may be eliminatedentirely.

The number and configuration of the fittings 14 of the manifold 12, aswell as the fittings 15 of the capsule filter 13, may be widely varied.In many embodiments the manifold 12 has three fittings 14 a, 14 b, 14 c.However, a manifold may have more than three fittings or fewer thanthree fittings. For example, where a vent is not preferred or where theinlet to the capsule filter or the outlet from the capsule filter is notdirected through the manifold, the manifold may have two fittings oronly a single fitting.

The fittings 14 of the manifold 12, as well as the fittings 15 of thefilter cartridge 13, may be structured in a variety of ways. Forexample, the fittings may be arranged in any regular or irregularpattern, such as a triangular pattern. Preferably, the fittings 14, 15are generally aligned. Further, the spacing between the fittings, or thepattern of the fittings, may be symmetric but is preferably notsymmetric. For example, as shown in FIG. 2, the distance between thevent fittings 14 c, 15 c and the outlet fittings 14 b, 15 b may be lessthan the distance between the outlet fittings 14 b, 15 b and the inletfittings 14 a, 15 a. A unsymmetric spacing or pattern helps to preventthe capsule filter from being installed “backwards” on the manifold.

The fittings may be structured in various ways. For example, each of thefittings may comprise a nozzle or a port or receptacle which receives anozzle. Some of the fittings on the manifold, or the capsule filter, maycomprise nozzles while others comprise receptacles, or all of thefittings on the manifold may comprise nozzles or receptacles. In theillustrated embodiment, the fittings 14 a, 14 b, 14 c of the manifold 12all preferably comprise nozzles 110 and the fittings 15 a, 15 b, 15 c ofthe capsule filter 13 all preferably comprise corresponding receptacles111 which receive the nozzles 110 of the manifold 12.

A wide assortment of nozzles and receptacles are suitable. However, thenozzle preferably includes a tip portion which contacts, and morepreferably seals against, a corresponding surface in the receptacle. Bycontacting and/or sealing the tip portion of each nozzle with acorresponding surface in the receptacle, gaps or leakage volumes at theends of the nozzles are eliminated, reducing the hold up volume andminimizing stagnant flow areas or dead zones within the filtrationsystem, and the filtration system may be made smaller. To enhance thesealing engagement of the tip portion of each nozzle and thecorresponding contact surface of the receptacle, at least the tipportion of the nozzle and the contact surface of the receptacle arepreferably formed from different materials, one harder and the other ofsimilar hardness or, more preferably, somewhat softer or moredeformable. As the tip portion of the nozzle engages the contact surfaceof the receptacle, the softer material deforms to the harder material,forming a highly effective seal. The sealing engagement of the contactsurface of the tip portion of the nozzle and the contact surface of thereceptacle is preferably free of any additional sealing member, such asa gasket, at the contacting surfaces and may comprise the only or theprimary seal between the fittings. However, additional seals spaced fromthe contacting surfaces, such as a supplemental O-ring seal, may also beprovided between the nozzle and the receptacle. The seal formed by thecontact surfaces may, for example, prevent any dead zones or stagnantportions from developing at the ends of the nozzle, while thesupplemental O-ring seal may ensure a liquid and/or air tight sealbetween the fittings.

Either the tip portion of the nozzle or the contact surface of thereceptacle may be formed from the harder material or the softermaterial. Because the capsule filter is preferably disposable and themanifold is preferably reusable, it is preferable to form the fitting onthe manifold, e.g., either the nozzle or the receptacle on the manifold,from the harder material. Examples of harder materials include metal,such as stainless steel, and polymeric materials, such as polyethylene,e.g., HDPE, polypropylene, PFA, ETFE, ECTFE, and PCTFE(polychlorotrifluoroethylene), which may be relatively harder than thematerial in the corresponding fitting. Examples of softer materialsinclude elasomeric-type materials, such as rubber, silicone, andpolyurethane, and polymeric materials, such as LDPE, FEP, PFA and PTFE,which may be relatively softer than the material of the correspondingfitting. Generally, any suitable combination of relatively hard andrelative soft materials may be used for the nozzle/receptaclearrangements based, for example, on a shore hardness D-scale, where PTFEis in the range from about 50 to about 56; ETFE is about 75; FEP isabout 55; PFA is about 60; PCTFE is about 90; ECTFE is about 75; PVDF isin the range from about 70 to about 80; LDPE is in the range from about40 to about 50; and HDPE and UHMWPE are in the range from about 60 toabout 70.

The nozzles and receptacles may be structured in numerous ways.(Components of the embodiments shown in FIGS. 26-41 have the samereference numbers as the analogous components of the embodiments shownin FIGS. 1-25.) Some of the many examples of nozzle/receptaclearrangements are illustrated in FIGS. 26-41. In each of the illustratedembodiments, the nozzle is operatively associated with the manifold andthe corresponding receptacle is operatively associated with the capsulefilter. However, one or more of the nozzles may alternatively beassociated with the capsule filter while the corresponding receptacle isassociated with the manifold.

In the embodiment shown in FIGS. 26 and 27, the manifold 12 may comprisea body 115, e.g., a polymeric body, and may further comprise a bottomplate 116, e.g., a metal plate, mounted to the body 115. A nozzle 110,which is preferably unitarily formed with the body 115, extends throughan aperture 118 in the bottom plate 116. A conduit 119, e.g., an inlet,outlet, or vent conduit, extends through the body 115 and the nozzle110, opening in the tip portion 120 of the nozzle 110.

The receptacle 111 of the capsule filter 13 may comprise a collar 126,e.g., a polymeric collar, which has a region defining a bore 127. A seat128, which preferably comprises a separate insert, may be positionedwithin the bore 127 on a ledge 129 of the collar 126. The seat 128 maybe formed from a material different from the material of the nozzle 110and also different from the material of the collar 126, the seat 128being preferably formed from a material which is softer or harder thanthe material of the nozzle 110 or the collar 126. For example, the seat128 may be formed from PTFE while the nozzle 110 and the collar 126 maybe formed from polyethylene, PFA or PCTFE. A seal, such as an O-ring130, may be positioned in the bore 127 on a rim of the seat 128 andaround the interior of the collar 126. A cap 131 may be mounted to thecollar 126 over the O-ring 130. The cap 131 has an opening 132 which islarge enough to receive the nozzle 110. The opening 132 in the cap 131,as well as the collar 126, the seat 128, and/or the tip portion 120 ofthe nozzle 110, and may be tapered to facilitate insertion of the nozzle110 into the receptacle 111. A conduit 133 extends through the collar126 and at least partially through the seat 128 and opens onto theopening 132 in the cap 131.

The tip portion 120 of the nozzle 110 and the seat 128 each have acontact surface 140, 142 which may be similarly or differently shaped.The configuration of each contact surface 140, 142 may vary. Forexample, the contact surfaces 140, 142 of the tip portion 120 and theseat 128 may have curved or tapered configurations such as a sphericalor conical configuration or a flat annular configuration. The area ofthe contact surfaces 140, 142 may be relatively wide but in manypreferred embodiments, the area of at least one of the correspondingcontact surfaces 140, 142 may be relatively narrow.

As the carriage moves from the disengaged position to the engagedposition and the nozzle 110 is inserted into the receptacle 111, theO-ring 130 seals against the nozzle 110. The O-ring 130 may also sealagain the rim of the seat 128, the inner wall of the collar 126 and/orthe cap 131. In addition, the contact surfaces 140, 142 of the nozzle110 and the receptacle 111 engage and at least the softer surface, e.g.,the contact surface 142 of the seat 128, preferably deform toeffectively seal against the harder surface, e.g., the contact surface140 of the tip portion 120 of the nozzle 110. As the nozzle 110 bearsagainst the seat 128, not only does the contact surface 142 of the seat128 seal against the contact surface 140 of the nozzle 110, but the seat128 also deforms and seals against the collar 128, e.g., against theledge 129 and/or the inner wall of the bore 127 of the collar 126. Bycontacting and sealing the seat 128 against the tip portion 120 of thenozzle 110 and the collar 126 of the receptacle 111, no gaps or leakagevolumes are created which can hold up fluid and cause dead zones orstagnant flow areas. Instead, the channel defined by the conduits 119,133 extending through the nozzle 110 and the receptacle 111 provides aflow path free of hold up volumes, leakage volumes, and dead zones, asshown in FIG. 27.

In addition to reducing hold up volumes, leakage volumes and dead zones,the nozzle/receptacle arrangement provides a more reliable filtrationsystem 10 and facilitates manufacture of the manifold 12 and the capsulefilter 13. For example, the dimensional variations associated with theaxial length of the nozzles 110, e.g., from the bottom plate 116 to thetip portion 120, may mean that nozzles 110 on the same manifold 12 havedifferent lengths. This variation may be accommodated by the deformationof the seat 128. Longer nozzles 110 may deform the seat 128 slightlymore than shorter nozzles 110 while both adequately seal the fittings.

In addition, eccentricities in the alignment and/or spacing of thenozzles 110 on the same manifold 12 may be accommodated by thedeformation of the seat 128 and the use of an insert for the seat 128,or the nozzle 110. The seat 128 and/or the nozzle 110 may be arranged tomove laterally as the fittings 14, 15, including the contact surfaces140, 142, contact one another. For example, the outer diameter of theseat 128 may be slightly smaller than the diameter of the bore 127 inthe collar 126, e.g., by about 0.2 mm. As the fittings 14, 15, includingthe mating tapered contact surfaces 140, 142, engage one another, theylaterally adjust the position of the seat 128 within the bore 127,centering the seat 128 on the nozzle 110. Further, any slight tilt ofthe axis of the nozzle 110 may be accommodated by an asymmetricaldeformation of the seat 128 about the axis of the nozzle 110.

Similar variations and eccentricities in the receptacle may also beaccommodated. By accommodating these variations and eccentricities,abnormal stresses and strains on the nozzles and receptacles may berelieved, providing a more reliable filtration system. Further, neitherthe manifold nor the capsule filter need be manufactured to extremelytight tolerances, reducing the cost of manufacture.

Other examples of the nozzle/receptacle arrangements are shown in FIGS.28-41 and may provide similar and/or additional features and advantages.(Components of the embodiments shown in FIGS. 28-41 have the samereference numbers as the analogous components of the embodiment shown inFIGS. 26 and 27.) The embodiment shown in FIGS. 28 and 29 is verysimilar to the embodiment shown in FIGS. 26 and 27. However, ridges 145may extend from the ledge 129 of the collar 126 toward the seat 128. Theengagement of the contacting surfaces 140, 142 of the nozzle 110 and thereceptacle 111 deforms the ridges 145 and/or drives the ridges 145 intothe seat 128 to better seal the seat 128 to the collar 126.Alternatively, the ridges may extend from the seat toward the ledge ofthe collar and may deform and/or be driven into and seal against theledge as the nozzle engages the receptacle.

In the embodiment shown in FIGS. 30 and 31, the seat 128 may comprise aunitary portion of the collar 126 rather than an insert. However, thenozzle 110 preferably comprises an insert sealed to the body 115 of themanifold 12, e.g., by an O-ring 146 disposed in a bore 147 at the upperend of the nozzle insert. The nozzle 110 may be formed from a differentmaterial, e.g., a harder material, than the collar 126 of the receptacle111 and/or from a different material than the body 115 of the manifold12. Variations and eccentricities may be accommodated by movement of theinsert and by deformation of one or both contacting surfaces, in amanner similar to that previously described. In addition, variation inthe length of the nozzles 110 may be accommodated by axial compressionof the O-ring 146. The contact surfaces 140, 142 are preferablysemi-spherical and may have a relatively broad contact area.

The embodiment shown in FIGS. 32 and 33 is similar to the embodimentshown in FIGS. 30 and 31. However, both the nozzle 110 and the seat 128may comprise inserts. The O-ring 146 sealing the nozzle insert isdisposed in a groove 147 around the outer periphery of the insert.Further, ridges 149 may be disposed between the nozzle insert and thebody 115 of the manifold 12, in addition to the ridges 145 between theseat insert and the ledge 129 of the collar 126. The ridges 149 mayextend from the body toward the nozzle insert or from the nozzle inserttoward the body. The engagement of the contacting surfaces 140, 141deforms the ridges 145, 149 and/or drives the ridges 145, 149 into theinserts to better seal the seat and nozzle inserts.

The embodiment shown in FIGS. 34 and 35 is similar to the embodimentshown in FIGS. 30 and 31. However, the receptacle 111 may not include acap. Rather, the collar 126 may have a rim 150 which faces the manifold12 and defines the opening 132 in the receptacle 111. The O-ring 130which seals against the nozzle 110 is disposed in a groove 151 in theinner wall of the collar 126 which defines the bore 127. In addition,the contact surfaces 140, 142 preferably have a conical configurationand at least one of the contact surfaces 140, 142, e.g., the contactsurface 142 of the seat 128, may have a relatively narrow contact area,which may enhance the seal between the contact surfaces 140, 142.

The embodiment shown in FIGS. 36 and 37 is similar to both theembodiment shown in FIGS. 34 and 35 and the embodiment shown in FIGS. 32and 33. The contact surface 142 of the seat insert has the relativelynarrow contact area.

The embodiment shown in FIG. 38 may comprise a nozzle 110, e.g., anozzle insert, which has a groove 155 in the outer wall. An O-ring 156is disposed in the groove 155 and provides a seal against the receptaclecollar 125 which supplements the sealing engagement of the contactsurfaces 140, 142.

The embodiment shown in FIG. 39 is similar to the embodiment shown inFIG. 38. However, the receptacle 111 may include a cap 131 and a seatinsert 128 comprising a spherical contact surface having a relativelynarrow contact area.

The embodiment shown in FIG. 40 is similar to the embodiment shown inFIG. 39. However, the tip portion 120 of the nozzle 110 may have acylindrical configuration and both contact surfaces 140, 142 may haveflat, annular configurations with relatively small contact areas.

The embodiment shown in FIG. 41 is similar to the embodiment shown inFIG. 40. However, the contact surfaces 140, 142 may have a reverseconical configuration in which the cone converges toward the axis of thenozzle 110 within the nozzle 110.

The fittings shown in FIGS. 26-41 include a nozzle and a correspondingreceptacle having mating contact surfaces which preferably serve as aseal, e.g., a primary seal or even the sole seal, between the fittings.However, other fittings between the manifold and the capsule filter maybe used. For example, fittings which are threaded, clamped and/orfriction fitted to one another may be used to seal the manifold to thecapsule filter.

The filters may also be configured in a variety of ways, including, forexample, as a capsule filter. One example of a capsule filter 13 isshown in FIGS. 42-46. The capsule filter 13 generally comprises ahousing 160 and a filter cartridge 161 removably or, preferably,permanently disposed in the housing 160.

The housing 160 may be formed from any suitably impervious material,e.g., a metal or a polymeric material, and may have any desired shape,e.g., a generally cylindrical shape. In many preferred embodiments, theshape of the housing corresponds to the shape of the filter cartridge.

The housing 160 may comprise a single piece structure but preferablycomprises a multi-piece structure. For example, the housing 160 mayinclude a bowl 162 and a head 163 removably or, preferably, permanentlyattached to the bowl 162. The bowl 162 may include a side wall and abottom wall. A handle 159 may extend outwardly from the side wall of thebowl 162 and may be used to position the capsule filter 13 on the baseassembly of the carriage with the protrusion 35 on the bottom of thecapsule filter 13 engaged in the slot in the base.

The housing 160 has one or more fittings, e.g., an inlet fitting 15 a,an outlet fitting 15 b, and a vent fitting 15 c. The inlet fitting 15 aand the outlet fitting 15 b define a fluid flow path through the housing160. The fittings may be variously configured, e.g., as nozzles. In theembodiment illustrated in FIGS. 42-45, the fittings each comprisereceptacles which may be similar to any of the receptacles previouslydescribed. One or more of the fittings may be disposed in the bowl,e.g., at the bottom or in the side wall of the bowl. Preferably,however, at least one and, more preferably, all of the fittings 15 a, 15b, 15 c are disposed in the head 163 on the top of the capsule filter13.

The housing 160 preferably contains the filter cartridge 161 within afilter cartridge chamber in the fluid flow path. The filter cartridgepreferably includes a filter element 170 having a filter medium, asshown in FIG. 46. The filter medium may comprise a solid or hollowporous mass, such as a cylindrical mass of sintered metal particles or acylindrical mass of bonded and/or intertwined fibers, e.g., polymericfibers. In many preferred embodiments, the filter medium may comprise apermeable sheet, e.g., a porous woven or non-woven sheet of fibers,including filaments, or a permeable or porous, supported or unsupportedpolymeric membrane, and the filter element 170 may have a cylindrical,hollow pleated configuration. The filter medium may be the sole layer ofthe pleated filter element 170 but is preferably one of two or morelayers of a pleated composite further including, for example, one ormore drainage layers, pre-filter layers, additional filter layers,substrates, and/or cushioning layers. The pleats of the filter elementmay extend radially or, preferably, non-radially, as disclosed, forexample, in U.S. Pat. No. 5,543,047 which is incorporated by reference.As disclosed in U.S. Pat. No. 5,543,047 non-radially extending pleatseach have a height greater than (D−d)/2 and less than or equal to(D²−d²)/[4(d+2t)] where D and d are the outside and inside diameters,respectively, of the pleated filter element at the crests and roots ofthe pleat and t is the thickness of a pleat leg. Preferably, the heightof each pleat is in the range from about 70% or 80% to about 100% of(D²−d²)/[4(d+2t)]. The non-radial pleats may be preferred because theremay be little or no space between the pleats, minimizing hold up volumeand dead zones.

The hollow filter element 170 is preferably disposed between a cage 171and a core 172. The ends of the filter element 170, the cage 171 and thecore 172 may be sealed to end caps 173, 174, e.g., a blind end cap 173and an open end cap 174. The open end cap 174 has an opening 175 whichfluidly communicates with the interior of the hollow filter element 170.The open end cap may be sealed or attached to the housing with theopening in the open end cap, in turn, fluidly communicating with afitting. For example, in the embodiment shown in FIGS. 42-45, the openend cap 174 may be bonded to the head 163 with the outlet fitting 15 bpreferably fluidly communicating with the interior of the filter element170 via the opening 175 in the open end cap 174. The inlet fitting 15 apreferably fluidly communicates with the exterior of the filtercartridge 161. Flow may then be directed outside in through the filtercartridge 161. Alternatively, the inlet fitting and the outlet fittingmay be arranged to fluidly communicate with the interior and theexterior, respectively, of the filter cartridge, and flow may bedirected inside out through the filter cartridge.

While the filter cartridge has been described in terms of a hollowfilter element 170 having a pleated filter medium, a cage 171, a core172 and end caps 173, 174, the filter cartridge is not limited to thisembodiment. Numerous alternative filter cartridges are suitable. Forexample, the filter element may have a filter composite which isspirally wound rather than pleated. The cage and/or the core may beeliminated. Further, one or both end caps may be eliminated, and theends of the filter element may be bonded directly to the top and/orbottom of the housing.

Yet other examples of filter cartridges may incorporate filter mediacomprising permeable hollow fiber media. For example, as shown in FIG.47, a capsule filter 13 may comprise a filter cartridge 161 which mayinclude permeable, e.g., porous, hollow fibers 180. (Components of theembodiment shown in FIG. 47 have the same reference numbers as theanalogous components of the embodiment shown in FIG. 45.) The hollowfibers 180 may be contained between end caps 181, 182, e.g., an open endcap 181 and a blind end cap 182. In particular, the hollow fibers 180may be potted in and extend from a partition 183 of the open end cap 181and loop back to the partition 183, one or both of the ends of thehollow fibers 180 being an open end fluidly communicating with theopening 184 in the open end cap 181. A perforated cage 185 may extendbetween the end caps 181, 182 around the hollow fibers 180.Alternatively, both end caps may be open end caps and the cage may haveno openings, the fluid being directed into the filter cartridge throughthe open lower end cap, or the cage and the blind end cap may beeliminated.

Another example of a capsule filter 13 comprising permeable hollowfibers 180 is shown in FIG. 48. (Components of the embodiment shown inFIG. 48 have the same reference numbers as the analogous components ofthe embodiment shown in FIG. 47.) In the embodiment shown in FIG. 48,the hollow fibers 180 extend between the partition 183 in the open endcap 181 and the blind end cap 182. One end of each hollow fiber 180 maybe blindly potted in the blind end cap 182, while the other end isopenly potted in the partition 183 in fluid communication with theopening 184 in the open end cap 181. A perforated cage may or may notextend between the end caps.

Regardless of the configuration of the filter cartridge, the interior ofthe housing is preferably fitted to the filter cartridge to minimizehold up volume and dead zones and to enhance fluid flow distribution andrise time within the housing. For example, as shown in FIG. 45, theinterior side wall of the bowl 160 and the exterior of the filtercartridge 161 may be similarly shaped, and the bowl 160 preferably fitsclosely completely around the filter cartridge 161, defining an annularfluid flow distribution channel between the interior of the bowl 160 andthe exterior of the filter cartridge 161. The annular channel ispreferably dimensioned to reduce hold up volume and to allow a sweep offluid flow around and/or axially along the filter cartridge withoutundue pressure drop between the inlet and outlet fittings. The desireddimensions of the annular channel may be determined empirically based onsuch factors as, for example, the viscosity of the fluid, the desiredflow rates and pressure drop limits and the area of the inlet or outlet,e.g., the inlet fitting or the outlet fitting. For many embodiments, theaxial cross sectional area of the annular channel may preferably be onthe order of, e.g., approximately equal to, the area of the inletnozzle.

Further, the interior bottom wall of the bowl 160 and the bottom of thefilter cartridge 161 may also be similarly shaped and closely fitted toone another. The bottom of the filter cartridge may completely contactand may be attached to the bottom wall of the bowl, eliminating anyspace between them. However, in many preferred embodiments, the bottomof the filter cartridge is fitted to the bottom of the housing with oneor more lower flow channels extending between them and communicatingwith the bottom of the annular flow channel. For example, the bottom ofthe filter cartridge, e.g., the bottom of the lower end cap, and/or theinterior bottom wall of the housing may have one or more radiallyextending ribs or spokes. The filter cartridge and the housing maycontact one another along the ribs and define the lower channels betweenthem. Further, the interior bottom wall of the housing and/or the bottomof the filter cartridge preferably have a surface which is inclinedupward to decrease the rise time of bubbles from the bottom of thefilter. For example, the lower flow channels may incline upwardly towardthe annular channel, preferably at an angle of about 15° or less, e.g.,about 10° or less. The lower channels are preferably dimensioned toreduce hold up volume, to allow a sweep of fluid flow between the filtercartridge and the bottom of the housing without undue pressure dropbetween the inlet and outlet fittings, and/or to facilitate clearance ofbubbles from the bottom of the filter. Again, the desired dimensions ofthe lower channels, including the degree of incline, may be determinedempirically based factors such as fluid viscosity, desired flow rates,pressure drop limits and inlet/outlet areas.

The interior wall of the head 163 may fit closely to the top of thefilter cartridge away from the vent fitting 15 c but is preferably atleast slightly spaced from the top of the filter cartridge 161 in thevicinity of the vent fitting 15 c, allowing gases to rise from theannular flow distribution chamber and over the top of the filtercartridge 161 toward the vent fitting 15 c. Preferably, the spacebetween the interior wall of the head 163 and the top of the filtercartridge 161, e.g., the top of the upper end cap, increasescontinuously from a location most distant from the vent fitting 15 c tothe vent fitting 15 c. Nonetheless, while the space between the interiorwall of the head 163 and the top of the filter cartridge 161 ispreferably sufficient to vent gas from the capsule filter 13, it is alsopreferably small enough to avoid excessive hold up volume.

In many, but not all, preferred embodiments, the housing may comprise afluid conduit, e.g., a fluid inlet conduit or a fluid outlet conduit,which extends from one of the fittings axially along the periphery ofthe filter cartridge chamber and is isolated from the filter cartridgechamber along a substantial length of the conduit, e.g., at least about50 percent of the length of the conduit. For example, the fluid conduitmay be disposed in the bowl, or adjacent to the bowl, and radiallybeyond the filter cartridge chamber. Preferably, the fluid conduitextends from a fitting at the top of the housing and opens into thefilter cartridge chamber, e.g., the annular flow distribution channel,at the bottom of the housing. As shown in FIG. 45, the fluid conduit 164may comprise an inlet conduit extending axially along the periphery ofthe filter cartridge chamber from the inlet fitting 15 a at the top ofthe housing 160 through the head 163 and the bowl 162 to the bottom ofthe housing 160. The inlet conduit 164 preferably communicates with theannular fluid flow distribution channel and the filter cartridge chamberonly at the bottom of the housing 160 and, therefore, is isolated fromthe filter cartridge chamber for at least about 70 percent, morepreferably at least about 80 percent or at least about 90 percent, ofthe length of the conduit 164.

The housing may also preferably comprise a radial passage through theside wall and/or more preferably in the interior bottom wall of thehousing which extends from the side wall of the bowl 162, and fluidlycommunicates with the axial fluid conduit. The radial passage may extendalong the lower end cap or along the bottom wall of the housing or alongboth, e.g., between the lower end cap and the bottom wall. For example,the radial passage may extend from the bottom of the fluid conduit,under the filter cartridge, e.g., under the lower end cap. The radialpassage may extend completely under the filter cartridge but preferablyextends only part way under the filter cartridge. As shown in FIG. 45,the radial passage 165 extends from the bottom of the fluid conduit 164under the filter cartridge 161, terminating near the center of thefilter cartridge chamber of the housing 160. The radial passage 165 mayhave a uniform cross section or a tapered cross section, e.g., the crosssection may decrease with increasing distance from the side wall of thebowl 162. The radial passage 165 may feed fluid to, or receive fluidfrom, the lower flow channels between the bottom of the filter cartridge161 and the bottom wall of the bowl 162 and may fluidly communicatebetween the lower flow channels and the axial fluid conduit.Alternatively, the radial passage may be eliminated, e.g., where thereare no longer flow channels between the bottom of the filter cartridgeand the bottom wall of the bowl.

Further, in many preferred embodiments the filter cartridge may comprisea keying mechanism cooperatively arranged between the housing and thefilter cartridge to center the filter cartridge in the filter cartridgechamber of the housing and provide a uniform annular flow channel. Thekeying mechanism may have any of numerous suitable structures. Forexample, the keying mechanism may comprise one or more centering pinsand mating centering apertures on the housing and the filter cartridgesimilar to the centering mechanism 80 previously described.

More preferably, one or both of the end caps, e.g., the lower end capand the corresponding wall of the housing may have mating profiles orshapes which center the filter cartridge in the filter cartridge chamberas the filter cartridge is mounted within the housing. The shapes may,for example, comprise curved or tapered configurations, e.g., apartially spherical, elliptical or conical configuration, on one or bothend caps and the corresponding wall of the housing. As shown in FIG. 45,the lower end cap 173 may have a generally conical configuration whichmates with a conical configuration in the interior bottom wall of thebowl 162 of the housing 160. The configurations are located and shapedto center the filter cartridge 161 in the filter cartridge chamber.Thus, as the filter cartridge 161 is mounted within the bowl 162 withthe configuration of the lower end cap 173 contacting the configurationof the interior bottom wall of the bowl 162, the filter cartridge 161automatically centers itself within the filter cartridge chamber of thebowl 162 due to the mating engagement of the conical configurations. Thehead 163 may then be attached to the bowl 162 and the upper end cap 174of the filter cartridge 161. A keying mechanism, such as matingconfiguration, e.g., conical configuration, in the interior wall of thehead 163, e.g., the region of the head 163 near the outlet fitting 15 b,and on the upper end cap 174, may center the filter cartridge 161 on thehead 163 as well as the bowl 162.

The housing including one or more of the axial fluid conduit, the radialpassage, and/or the keying mechanism may be fabricated in any suitablemanner. For example, a molded bowl 162 is illustrated FIGS. 49 and 50.The bowl 162 may be molded in two pieces, e.g., a side wall piece 195and a bottom wall piece 196, and the two pieces 195, 196 may beattached, e.g., welded or bonded, to form the bowl 162. In theillustrated embodiment, the bowl 162 includes an axial fluid conduit164, a radial passage 165, a filter cartridge chamber, and a centeringconfiguration 191 in the interior bottom wall of the bowl 162.

Alternatively or additionally, the housing may be machined. For example,a machined bowl 162 is illustrated in FIGS. 51 and 52. The machined bowl162 preferably comprises a unitary piece 197. A filter cartridge chamberand an axial fluid conduit 164 may be bored in the unitary piece 197. Aradial passage 165 may be bored through the side wall of the unitarypiece 197, and the exterior end of the radial passage 165 may be pluggedor fitted with a fitting.

Capsule filters having one or more of the axial fluid conduit, theradial passage, and/or the keying mechanism have many advantages andrepresent a significant advance in the art. These features are even morevaluable when combined with the close fit between the housing and thefilter cartridge and the non-radial pleats of the filter cartridge. Forexample, the axial fluid conduit allows the fluid to sweep evenly alongthe axial length of the filter cartridge from the bottom to the top ofvice versa, reducing or eliminating dead zones at the bottom or top ofthe annular channel. The radial passage coupled to the lower channelsunder the lower end cap further enhances the even distribution of fluidflow in the annular fluid channel around the filter cartridge andfurther avoids dead zones at the bottom of the annular channel. Thekeying mechanism ensures that the filter cartridge is centered in thefilter cartridge chamber and provides a uniform annular channel, evenfurther enhancing the even distribution of fluid flow around the filtercartridge. These advantages combined with the low hold up volumeprovided by the close fit between the housing and the filter cartridgeand by the non-radial pleats of the filter cartridge provide a filterwith far superior performance than conventional filters with respect toreducing hold up volume and dead zones, providing an even distributionof fluid flow upward, or downward, along the filter cartridge;sharpening rise time; and minimizing the time to output of a fluid whichhas a desired level of cleanliness and is substantially free of gasbubbles.

The present invention has been described in terms of severalembodiments. However, the invention is not limited to these embodiments.For example, one or more of the features of one embodiment may beeliminated or combined with one or more of the features of anotherembodiment without departing from the scope of the invention. Further,entirely different embodiments may be envisioned, particularly in lightof the foregoing teachings. Accordingly, the invention includes allvariations and modifications encompassed with the scope of the attachedclaims.

1. A filtration system comprising: a manifold which includes an inletfitting and an outlet fitting, each fitting having an axis; a filterwhich includes a housing and a filter element disposed in the housing,wherein the housing includes an inlet fitting and an outlet fitting,each fitting having an axis and being positioned on top of the housing;a carriage which supports the filter with the fittings of the filterrespectively axially aligned with the fittings of the manifold; amounting mechanism arranged between the manifold and the carriage tomove the carriage and the filter between a disengaged position in whichthe fittings of the filter are axially aligned with and spaced from thefittings of the manifold and an engaged position in which the fittingsof the filter respectively engage the fittings of the manifold, whereinthe filter moves in a direction parallel to the aligned axes of thefittings of the filter and the manifold along all of the distance thatthe filter travels on the carriage; and a positioning mechanism arrangedbetween the carriage and the filter to axially align the inlet andoutlet fittings of the filter with the inlet and outlet fittings of themanifold in the disengaged position of the mounting mechanism.
 2. Thefiltration system of claim 1 wherein the mounting mechanism comprises apivotable lever arrangement which includes a pivotable lever coupledbetween the manifold and the carriage, wherein the lever pivots to movethe carriage and the filter between the disengaged and engagedpositions.
 3. The filtration system of claim 1 wherein the mountingmechanism includes a threaded arrangement cooperatively arranged betweenthe manifold and the carriage, the threaded arrangement including athreaded stud and a mating nut, wherein the threaded stud rotates withinthe nut to move the carriage and the filter between the disengaged andengaged positions.
 4. The filtration system of claim 1 wherein themounting mechanism includes a cam arrangement having a cam slot and apin or lever which travels along the cam slot to move the carriage andthe filter between the disengaged and engaged positions.
 5. Thefiltration system of claim 1 further comprising a pump fluidly coupledto the manifold.
 6. The filtration system of claim 1 wherein themanifold further includes a vent fitting and the filter further includesa vent fitting, each vent fitting having an axis, and wherein the inletfitting, the outlet fitting and the vent fitting of the filter arepositioned on top of the filter spaced from one another.
 7. Thefiltration system of claim 1 wherein the positioning mechanism includesan opening and a protrusion which is received in the opening.
 8. Thefiltration system of claim 7 wherein the opening includes a slot on thecarriage, the protrusion being on the filter.
 9. The filtration systemof claim 1 further comprising a seal sealing the engaged inlet fittingsand a seal sealing the engaged outlet fittings of the filter and themanifold.
 10. The filtration system of claim 1 wherein the manifoldfurther includes a vent fitting having an axis and the filter furtherincludes a vent fitting having an axis and wherein the inlet fitting,the outlet fitting, and the vent fitting of the filter are positioned ontop of the filter spaced from one another, wherein said positioningmechanism axially aligns the inlet, outlet and vent fittings of thefilter with the inlet, outlet and vent fittings of the manifold in thedisengaged position of the mounting mechanism, and wherein thefiltration system further comprises a seal sealing the engaged inletfittings, a seal sealing the engaged outlet fittings, and a seal sealingthe engaged vent fittings of the filter and the manifold.